The invention concerns a sorting device for laminae, especially for inlaid floor laminae of wood with a basically horizontally extending transport track for the laminae, with at least one delivery point for discharge of the laminae to be sorted out of the transport track, and with a delivery track proceeding out of the delivery point, whereby the delivery point is provided with a deflection apparatus for diverting the laminae to be sorted out to the delivery track.
Such sorting devices are in particular used in the manufacture of surface layer laminae for wood inlaid floors. Since wood is a natural product, the freshly manufactured laminae as a rule manifest different surface structures. As surface layer lamina for qualitatively high grade inlaid floors, however, only laminae with uniform graining, and especially without irregularities caused by branch attachment points, may be used. There are, however, various gradings according to quality standards.
The sorting of inlaid floor laminae according to quality grades usually still takes place by hand. Nevertheless, automatically operating sorting facilities with devices of the type mentioned above are being used in recent times to attain a higher through-put in sorting. The laminae to be sorted are separated on a transport track from a supply magazine, on which they are transported basically standing horizontally on their on one of their narrow sides. A camera is installed on this transport track through which the quality of the inlaid floor laminae scanned by the camera is recognized. A central control unit of the facility allocates the quality recognized to a certain delivery point within the transport track and actuates a deflection apparatus installed there at the point in time at which the appropriate lamina passes the delivery point. The lamina is then pushed laterally by the deflection apparatus out of the transport track and falls on a delivery track running crosswise in relation to the transport track, which guides it to a collection point at which laminae of homogenous quality are collected.
A through-put of about 150 inlaid floor laminae per minute can be attained with a sorting facility of the type just described. The rate of processing is nevertheless restricted by the fact that railing-like guide elements are necessary in order to protect the laminae transported in a standing position from falling over, and that interruptions of these guide elements must be correspondingly provided, as well as afterward catching devices for laminae which have not been discharged. The railing-like guide elements in addition exert a braking action on the laminae due to the effect of friction, in contrast to which the friction between the laminae and the transport track constructed as a conveyor band is relatively small, as the laminae are only standing on one of their narrow sides on the conveyor band.
With this state of the art, standing transport of the laminae on the transport track is deliberately preferred to transportation lying down, as such a transport indeed makes the railing-like guide elements just mentioned superfluous, but nonetheless brings considerable speed-limiting problems at the delivery point along with it, as pushing the laminae off laterally is associated with disadvantageous delays due to the high friction between the laminae and the conveyor band: With a conveying speed of 1 m/sec., a gap of 25 cm must in any given case be left free between the individual inlaid floor laminae in order to be able to tolerate a discharge delay of 0.25 seconds without blocking effects.
Proceeding from this state of the art, underlying the invention is the object of improving a sorting device of the type mentioned at the beginning so that higher operating speeds and a higher through-put of laminae are attainable.
This objective is accomplished by a device with the features of appended patent claim 1.
Advantageous configurations and refinements of the invention are apparent on the basis of patent claims 2 to 11.
The solution of the invention thus deviates from the previously known way of standing transport of the laminae and makes use of the advantages of transportation lying down. The disadvantages of lying down transport are avoided by a new delivery principle: The deflection apparatus transmits an upwardly directed impulse to the laminae as needed so that the laminae are lifted upwardly from the transport track. As it immediately becomes apparent, at the moment of deflection of a lamina, its adhesive friction is reduced to zero so that the delivery process can take place completely without delay. Since the laminae are not thrown out crosswise in relation to the direction of transport, but rather only receive an additional upward impulse, their kinetic energy on the basis of the transport process is used for the discharge process. In this way, higher transport speeds are realizable without negative effects upon the discharge process. Through the principle of power thrust or impulse transmission, even uneven inlaid floor laminae can be discharged trouble-free in a defined manner without delay.
The deflection apparatus for transmitting an upwardly directed impulse to the laminae can be a device for generating an air thrust, for example a controllable jet connected with a compressed air system which acts upon the laminae through a gap or an aperture in the transport track. The deflection apparatus can also be a simple actuator or a tilting panel functioning as a switch arranged in the transport track.
Particular advantages arise through an additional guide element which is arranged above the delivery point and which serves for passing laminae diverted upwardly by the deflecting apparatus to the delivery point. An air thrust used, for example, to deflect must then not transmit an exactly calculated, defined impulse. Rather it suffices for the impulse transmitted to exceed a minimum value so that the corresponding lamina also reaches the delivery track. An excessively high impulse is then intercepted by the guide element, and a defined transfer of the laminae to the delivery track takes place in any case. The guide element can be dimensioned such that laminae of the most varied length can be reliably discharged. It then suffices for the front end of the laminae to be acted upon by a sufficiently strong impulse to conduct the discharge process.
Further particular advantages become apparent when the guide element just mentioned is constructed such that the motion of the diverted laminae is accelerated in the direction of the delivery track. This brings about an active upward withdrawing of the laminae to be discharged which prevents any disadvantageous delay in the discharge process. The acceleration can, for example, be realized by constructing the guide element as a driven conveyor against which the laminae to be discharged are pressed by the upwardly directed impulse of the deflection apparatus. In order to increase the friction between the laminae to be discharged and the guide element constructed as a conveyor band, the latter can be provided with a vacuum apparatus to suck up the diverted laminae, on the basis of which a suction conveyor band for hanging transport results.
The delivery track is appropriately constructed as an ascending conveyor band so that the direction of motion of the laminae, except during deflection at the delivery point, no longer needs to be altered. Thus very high conveyance speeds are also manageable with correspondingly high kinetic energies.
In this manner, further advantages emerge if a basically horizontally arranged deceleration band running crosswise to the delivery track is connected to the delivery track such that the delivery track throws the laminae from the ascending inclination onto the deceleration band. In this way, the individual laminae fall flat on the deceleration band and do not strike perhaps first with their front end on this. The increased adhesion friction due to plane-parallel contact of the laminae on the deceleration band, which serves to brake the transport motion, further contributes to making higher transport speeds, and therewith higher through-puts through the sorting device, manageable.
Finally, even the transport track can be provided with a conveyor band and an associated vacuum apparatus. In this way, the friction between the laminae to be sorted and the transport track is increased once again which also makes possible very high transport speeds with correspondingly high laminae through-put.